package com.the9tcat.funnyalarmclock.oauth;

import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

/**
 * @author jianhpin
 */
public class OauthSignature {
	
	private final static char last2byte = (char) Integer.parseInt("00000011", 2);

    private final static char last4byte = (char) Integer.parseInt("00001111", 2);

    private final static char last6byte = (char) Integer.parseInt("00111111", 2);

    private final static char lead6byte = (char) Integer.parseInt("11111100", 2);

    private final static char lead4byte = (char) Integer.parseInt("11110000", 2);

    private final static char lead2byte = (char) Integer.parseInt("11000000", 2);
    
    private final static char[] encodeTable = new char[] {
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
        'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
        'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

public static String base64(byte[] from) {
    StringBuffer to = new StringBuffer((int) (from.length * 1.34) + 3);
    int num = 0;
    char currentByte = 0;
    for (int i = 0; i < from.length; i++) {
        num = num % 8;
        while (num < 8) {
            switch (num) {
                case 0:
                    currentByte = (char) (from[i] & lead6byte);
                    currentByte = (char) (currentByte >>> 2);
                    break;
                case 2:
                    currentByte = (char) (from[i] & last6byte);
                    break;
                case 4:
                    currentByte = (char) (from[i] & last4byte);
                    currentByte = (char) (currentByte << 2);
                    if ((i + 1) < from.length) {
                        currentByte |= (from[i + 1] & lead2byte) >>> 6;
                    }
                    break;
                case 6:
                    currentByte = (char) (from[i] & last2byte);
                    currentByte = (char) (currentByte << 4);
                    if ((i + 1) < from.length) {
                        currentByte |= (from[i + 1] & lead4byte) >>> 4;
                    }
                    break;
            }
            to.append(encodeTable[currentByte]);
            num += 6;
        }
    }
    if (to.length() % 4 != 0) {
        for (int i = 4 - to.length() % 4; i > 0; i--) {
            to.append("=");
        }
    }
    return to.toString();
}
	
    public static String sign(String data, String key) {
        byte[] byteHMAC = null;
        try {
            Mac mac = Mac.getInstance("HmacSHA1");
            SecretKeySpec spec = new SecretKeySpec(key.getBytes(), "HmacSHA1");
            mac.init(spec);
            byteHMAC = mac.doFinal(data.getBytes());
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException ignore) {
        }
        String oauth = OauthSignature.base64(byteHMAC);
        return oauth;
    }
    
    /** 对Java默认的URL编码后进行调整 */
    public static String oauthUrlEncode(String str) {
        String code = URLEncoder.encode(str);
        int len = code.length();
        StringBuffer sb = new StringBuffer(len);
        for (int i = 0; i < len; i++) {
            char focus = code.charAt(i);
            if (focus == '%') {
                sb.append("%25");
            } else {
                sb.append(focus);
            }
        }
        return sb.toString();
    }
    
    /** Java标准URL编码 */
    public static String normalUrlEncode(String str) {
        return URLEncoder.encode(str);
    }
}
